This invention relates generally to shipping and storage containers, and more particularly to a container for bulk, liquid and granular materials, which is collapsible and/or reusable or recyclable.
Effective, reliable, safe and economical packaging of bulk products for handling, transport and storage has been a concern for many years. Bulk products requiring such packaging vary widely from semi-solids such as meat and other such food items; to granular materials such as beans, peas, grains, rice, salt, flour, sugar, dry chemicals, dry cementitious products, animal feeds, fertilizers, etc.; to liquid materials such as syrups, milk, juices, glues, inks, resins, paints, chemicals, and the like. Since such materials have a tendency to move or flow, containment of them for shipment, handling and storage raises many challenges. It is desirable to package such materials in containers that can be readily transported by truck, rail or ship and which can be easily handled during transport and at a final destination such as at a processing facility by readily available equipment such as fork lifts, cranes and the like. The flowable nature of such products presents unique packaging issues for the container. Movement or shifting of the materials during transport can cause deformation of the container that can result in load shifting and instability and bursting containers, often with enough force to damage or destroy the container. The result is loss or damage to the container contents and undue cleanup and environmental concerns. The containers must even be more stable if stacked on top of each other.
The packaging industry has to date generally used two primary containment approaches: (1) corrugated bulk box containers (both plastic and paper); and (2) large bulk bags of woven fabric generally referred to as flexible intermediate bulk containers (FIBCs). Both approaches use various configurations of liners, typically made of polyethylene or polypropylene, that fit within the corrugated bulk box or within the FIBC for preventing contamination of the product being shipped and, in the case of a liquid product, to contain the liquid. Both packaging approaches use containers typically configured to be supported by and carried on pallets.
Utilizing the corrugated bulk box approach, the container strength needed to handle the wide variety of weight and product consistency requirements is addressed by using different strength grades of corrugated board materials and/or by increasing the wall thickness of the boxes by gluing corrugated sheets together or by inserting a corrugated sleeve into the box. Another approach for strengthening the box container is to wrap a number of plastic or steel straps around the outside periphery of the box. Both techniques suffer shortcomings. The price of the bulk box significantly increases with increased wall thickness and/or numbers of corrugated layers or higher quality corrugated materials. If the box board wall strength and/or thickness is reduced in order to cut costs, and a number of external support straps or bands are used, product pressure against the thinner box walls generally caused the box to bulge outwardly between the straps, resulting in a container having marginal safety factor and leading to numerous costly box failures in shipment.
The FIBCs utilize various fabrics (such as woven polypropylene and PVC coated fabrics) and various fabric weights and sewing methods, depending on the necessary strength of the bag and its desired factor of safety. Such bags vary in size to generally hold from 5 to 120 cubic feet of material and up to about 5,000 pounds of product. They generally can be designed with various shaped tops suitable for filling, can have a solid bottom or a sewn in discharge spout configuration, and may have lifting handles. For dry or fluidized products that require a more rigid bag for stability, solid support inserts may be placed inside the bag, and between the outer bag surface and a liner (if one is used) to provide the bag""s sidewalls with more rigidity. Because of the cost of the manufacturing sewing operations and the cost of the rigidity enhancing inserts used in the FIBCs, they typically result in a more expensive container than their corrugated box with strapping counterparts. If used without significant rigidity supports to store liquid materials, the FIBC bag will act like a large water balloon; thereby making the FIBCs more practical for use in shipping and storing dry bulk products. Further, the inserts that are typically placed within the FIBCs to provide sidewall rigidity are joined/hinged at their corners to fold down flat when not in use, and do not have bottoms. Without rigid bottoms, the inserts are susceptible to deformation from their intended footprint configuration during loading of the FIBC, resulting in a misshaped containment system that is unstable before and during shipment. To address this problem, collapsible metal grid cages have been configured to externally support the FIBC, further adding to the cost and use inflexibility of such systems for containing liquids.
The present invention addresses the problems and shortcomings of both the prior corrugated box and the FIBC containment systems. The present invention combines the strength of woven polypropylene materials used in the FIBC technology with unique configurations of inserts using the corrugated box technology, to create a very strong container that is easy to set up, maintains its shape during loading, which is significantly more cost effective, and which is safer and more reliable than heretofore known packaging methods.
This invention uses existing industry accepted packaging materials to form a unique bulk container system that is universally applicable to the packaging of solid; semi-solid, granular or liquid materials. The bulk container system of this invention combines the advantageous features of known packaging techniques in a unique manner without suffering their respective short comings. An internal forming member or insert of relatively inexpensive light weight corrugated material is used to define an internal geometric volumetric shape of the container in a manner that does not change shape or collapse during loading. The forming member is collapsible for storage and is easily erected by folding to an operable box-like configuration. The forming member insert has a unique bottom design that when assembled, squares-up and locks the forming member sidewalls in predetermined positions to define a desired geometric volume. The forming member is designed to be placed on and carried by a pallet.
An outer tubular sleeve, that can be configured without stitching or seams, is sized to surround and snugly engage the entire outer peripheral sidewall areas of the forming member, and assumes the defined geometric shape of the outer surface of the forming member. The sleeve, preferably of woven polypropylene material, provides the necessary strength for containing the bulk material within the forming member insert, while the insert provides the desired rigidity and shape to the system. Together, they form a stable, multi-purpose and universal container system configuration that is less expensive than either corrugated or FIBC known container configurations. Both the insert and sleeve components of the container system can be collapsed for reuse and are completely recyclable. A standard liner can be inserted within the forming member to protect the contents from contamination or the environment and/or to retain liquids.
The forming member insert can be configured to any desired shape, as dictated by the intended use of the container system. The size of the container and the weight of its contents will dictate the strength of the outer sleeve, which will be of a food grade fabric for food containment applications. The invention also includes forming member configurations that allow relative movement between cooperating portions thereof, such that the insert can expand and contract with the contained contents of the system. Another feature of the invention is a forming member insert design that maintains a given footprint configuration of the container, but which allows the upper portion of the container to reconfigure along predetermined expansion lines to reduce stress across the insert sidewalls.
According to one aspect of the invention, there is provided a container for bulk materials, comprising (a) a forming member comprising a plurality of sidewalls extending between upper and lower edges and interconnected to cooperatively form an outer surface and to encircle an internal cavity for receiving bulk materials, and a locking assembly cooperatively engaging the sidewalls to define and fix predetermined relative positions thereamong; and (b) a sleeve of continuous material sized to snugly engage and to overlie substantially entire outer surface of the sidewalls. According to a further aspect of the invention, the forming member comprises a single piece of material and may be of corrugated construction and collapsible when the locking assembly is not operable to fix the positions of the sidewalls. According to a further aspect of the invention the sleeve comprises a continuous seamless woven material that is tubular and nature and does not have a bottom surface. According to yet a further aspect of the invention, the sleeve is configured to define a fold extending upward from the lower edges of the sidewalls to provide double strength adjacent the lower edges of the sidewalls, and preferably extends upward from the lower edges from about 20% to 50% of the height of the sidewalls. According to yet a further aspect of the invention, the sidewalls are configured for relative sliding engagement with one another to accommodate expansion and contraction of bulk materials contained by the container.
According to yet a further aspect of the invention there is provided a method of configuring a container for bulk materials comprising the steps of: (a) providing a forming member of the type having a plurality of sidewalls extending between first and second edges; (b) arranging said sidewalls in a closed manner such that they collectively define an internal cavity longitudinally extending between the planes defined by the first and second edges; (c) providing a locking assembly; (d) engaging the locking assembly with the sidewalls to fix the geometric shape of the internal cavity defined thereby; (e) providing a circumferentially continuous length of tubular sleeve material; and (f) snugly engaging the tubular sleeve around the outer periphery of the sidewalls such that the sleeve engages substantially the entire outer surface area of the sidewalls.
According to yet a further aspect of the invention there is provided a kit for a bulk material container, comprising: (a) a forming member comprising a plurality of sidewalls extending between upper and lower edges and configured for interconnection to cooperatively form an outer surface and to encircle an internal cavity for receiving bulk materials, and a locking assembly configured to cooperatively engage the sidewalls to define and fix predetermined relative positions thereamong; and (b) a sleeve of continuous material sized to snugly engage and to overly substantially the entire outer surface of said sidewalls.
These and other features of the invention will become apparent upon a more detailed description of preferred embodiment of the invention as described below.